Ambulances, fire trucks, police cars, and other emergency vehicles utilize warning lights to produce light signals of various colors and patterns. These warning lights must provide a bright, reliable light signal under all operational conditions encountered by the emergency vehicle on which the light is installed. The warning lights must therefore be temperature and moisture resistant, as well as resilient to vibration or other physical stresses during operation.
Obtaining desirable operational characteristics in a warning light can be difficult to achieve in a low power, small size, easy to use assembly. For example, mechanical or electrical structures may be incorporated into the warning light to assist with reliability, but may add size or weight to the warning light, or may otherwise increase the heat generation of the warning light. Or, in order to reduce heat dissipation, a lower power light source may be used; however, such a design choice can result in a dimmer light production than otherwise would be available.
Certain light assemblies use light emitting diodes (LEDs) as a light source. The light output of an LED can be highly directional. This directionality has been a detriment when trying to couple LEDs with parabolic reflectors in lighting assemblies. The directionality of an LED, taken together with the desire to shape the light output in different and sometimes opposite ways to yield a desired performance specification, has resulted in LED lighting systems that frequently employ lens elements in addition to reflectors to shape the beam. These LED-lens-reflector systems can suffer from poor optical efficiency, as well as the above-stated problems.
For these and other reasons, improvements are desired.